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date: 10 December 2023

Competency to Stand Trial in the American Legal Systemfree

Competency to Stand Trial in the American Legal Systemfree

  • Ronald RoeschRonald RoeschDepartment of Psychology, Simon Fraser University


Competency to stand trial is a long-established legal principle in the U.S. criminal justice system that ensures that a criminal defendant’s right to a fair trial is protected. Fundamental justice requires that criminal defendants should be able to understand the charges against them, appreciate the nature and range of penalties, and communicate with their attorney. If they do not have the capacity in any of these areas, they may be found incompetent to proceed and the judicial proceedings are suspended until they are treated and competency is restored.

While competency to stand trial is the most commonly used term, competency in the criminal trial process encompasses all stages of participation in the legal process, including pretrial, trial, sentencing, and appeals. It is also a consideration if a defendant chooses to represent him or herself. Indeed, the term itself is misleading because few defendants actually go to trial, as the vast majority of cases are resolved through plea bargaining. The competency issue is raised when an officer of the court (defense, prosecution, or judge) has reason to believe there is a bona fide doubt as to a defendant’s competence. Once raised, defendants are typically referred for an evaluation by a mental health professional. Legal precedence has established that the basis of a finding of incompetency must be the presence of a major mental illness or substantial cognitive deficit. However, the mere presence of either of these conditions is not sufficient, as a functional approach to assessing competency dictates that the mental illness or cognitive deficit must be shown to affect the defendant’s specific legal competencies. It is entirely possible, for example, that some defendants with a psychosis or other severe mental illness may nevertheless be able to proceed with their case if the mental illness does not impair the legal abilities necessary to go forward.


  • Clinical Psychology: Disorders and Therapies
  • Forensic Psychology


The principal that a criminal defendant has a right to a fair trial has long been a fundamental component of the American criminal justice system. Legal procedures that protect the rights of criminal defendants have been adopted to ensure that they have the capacity to participate fully in their defense (Youtsey v. United States, 1899; Dusky v. United States, 1960). The legal principle is usually referred to as competence to stand trial, although terms such as fitness to stand trial, adjudicative competence, and competence to proceed are also used (Bonnie, 1992; Golding, 2016). Bonnie noted that prohibiting incompetent defendants from proceeding with trial is essential to preserve the dignity of the judicial process, the reliability or accuracy of the court’s verdict, and the autonomy of defendants to make key decisions about their case.

This article will review laws and practices related to competency to stand trial in adult criminal populations. Competence issues also arise in noncriminal settings such as immigration removal proceedings (Filone & King, 2015), but that is beyond the scope of this article. Competence for execution is an infrequently raised competence issue, and the reader is referred to Zapf (2016) for a review and discussion. As well, assessments of juveniles are increasingly becoming more common, but the issues of concern focus more on developmental factors like maturity (Ryba, Cooper, & Zapf, 2008) rather than mental illness (see Kruh & Grisso, 2009; Roesch & Viljoen, 2016; Warren et al., 2009).

The modern standard for defining competence to stand trial was established in Dusky v. United States (1960), in which the U.S. Supreme Court held:

It is not enough for the district judge to find that “the defendant is oriented to time and place and has some recollection of events,” but that the test must be whether he has sufficient present ability to consult with his lawyer with a reasonable degree of rational understanding—and whether he has a rational as well as factual understanding of the proceedings against him.

(p. 402)

Dusky is a vague standard as it provides little clear direction to forensic examiners asked to provide an assessment of a defendant’s competence. The practice has evolved to assess first if a defendant has a psycholegal ability incapacity and if so, whether the defendant’s mental status (mental illness or intellectual deficit) is causally connected to that incapacity. Several subsequent cases have further defined the nature and scope of a competency determination (Drope v. Missouri, 1975; United States v. Duhon, 2000).

The term competence to stand trial is perhaps misleading because only a small percentage of criminal cases actually go to trial. Rather, the majority of cases are resolved through plea bargaining. Competence has come to refer to all aspects of participation in the legal process, from pretrial through sentencing and later in the appeal process. Competence is also a consideration when a defendant chooses to represent him or herself (referred to as proceeding pro se). Competence can even arise in death penalty cases in which the competence to proceed with appeals or to be executed is questioned (Cunningham, 2013). One of the first cases to consider the question of the range of competencies was Godinez v. Moran (1993), in which the U.S. Supreme Court held that the standard for various types of competency (i.e., competency to plead guilty, to waive counsel, or to stand trial) should be considered the same. Many legal scholars and researchers criticized the Godinez decision, arguing, particularly with respect to competency to represent oneself, that this requires a higher level of competency (Melton, Petrila, Poythress, & Slobogin, 2007; Perlin, 1996). Perlin cited the case of Colin Ferguson, who was accused of murdering six people and injuring 19 others on the Long Island Rail Road. He was allowed to represent himself, and his behavior during the trial led Perlin to comment that the Godinez decision resulted in a trial in which dignity, a prerequisite for a fair trial, was not preserved.

The Supreme Court revisited this issue in the case of Indiana v. Edwards (2008). The specific issue there was whether the standard for competency to stand trial and competency to represent oneself should be the same. The defendant Ahmad Edwards attempted to steal a pair of shoes from a department store in Indiana, and when security officers tried to apprehend him, he fired shots at them. He was subsequently charged with attempted murder, battery with a deadly weapon, criminal recklessness, and theft. He was diagnosed with schizophrenia and found incompetent to stand trial and remanded for treatment, which successfully restored his competence. A second evaluation in 2002 was requested by his attorneys, and he was found to be competent, but they requested a third evaluation in which he was found to be incompetent. Restoration was again successful, and he was allowed to proceed with adjudication. Subsequently, Edwards asked to proceed pro se, but this was denied by the trial judge. He was represented by counsel and convicted of the attempted murder and battery charges. The case carried through the appeals process and was eventually heard by the U.S. Supreme Court, which held that a trial judge can deny a defendant the right to proceed pro se even if he or she had previously been found competent.

Competency Procedures

If any officer of the court (defense, prosecution, or judge) has reason to believe there is a bona fide doubt as to a defendant’s competence, the issue must be raised in court, and failure to provide a defendant with a hearing to determine competency when there is sufficient evidence that competency may be an issue is a violation of the defendant’s sixth amendment right to a fair trial (Pate v. Robinson, 1966). The Supreme Court later held in Drope v. Missouri (1975) that “evidence of a defendant’s irrational behavior, his demeanor at trial, and any prior medical opinion on competence to stand trial are all relevant in determining whether further inquiry is required, but that even one of these factors standing alone may, in some circumstances, be sufficient” (p. 180). Once the issue is raised, the trial court will typically request an evaluation. Most competency evaluations are typically done by psychologists or psychiatrists, but social workers are also qualified in some states to conduct these evaluations (Jenkins v. United States, 1962; Roesch, 2015). Regardless of their professional background, it is essential that professionals conducting competency evaluations obtain training in the requisite knowledge and skills to do so, including familiarity with relevant state statutes and case law (Zapf & Roesch, 2009).

Criminal trial competency is raised substantially more often than other pretrial forensic assessment issues such as criminal responsibility. It is difficult to get an accurate estimate of the annual rates nationally. Bonnie and Grisso (2000) estimated some 60,000 annual evaluations, a figure that was a substantial increase over prior estimates (Hoge et al., 1997). Others have estimated that 2–8% of all felony defendants are referred each year for an evaluation of competency (Hoge, Bonnie, Poythress, & Monahan, 1992; LaFortune & Nicholson, 1995). It is likely that the number is higher today given the increase in mentally ill individuals in jail (Steadman, Osher, Robbins, Case, & Samuels, 2009). Most of those referred for competency evaluations are found competent after relatively brief assessments, but approximately 20–25% are found incompetent and referred for treatment to restore competency. Competency restoration practices are reviewed later.

A Functional and Contextual Approach to Defining and Assessing Competency

Grisso (2003) defined functional abilities as “that which an individual can do or accomplish, as well as to the knowledge, understanding, or beliefs that may be necessary for the accomplishment” (pp. 23–24). What are the functional abilities required by defendants to be considered competent to proceed with the legal proceedings? Murrie and Zelle (2015) reviewed the literature and identified five essential capacities: (1) a factual understanding of the legal proceedings, (2) an appreciation of how the factual understanding can be applied to his or her case, (3) an ability to make reasonable and logical decisions, (4) an ability to assist and communicate with counsel, and (5) an ability to make decisions about issues such as whether to accept a plea agreement, proceed with trial, testify, and the many other decisions faced by defendants in criminal cases.

The presence of mental illness or intellectual deficit is a key component of a competency evaluation, but mere presence of mental illness or deficit is not sufficient for a determination of incompetence. To be sure, the presence of a severe mental disorder such as a psychosis is an important first step in the evaluation of competence (Rosenfeld & Wall, 1998). The presence of psychosis, for example, is associated with a finding of incompetency. In a meta-analysis of 68 studies conducted between 1967 and 2008, Pirelli, Gottdiener, and Zapf (2011) found that defendants diagnosed with a psychotic disorder were eight times more likely to be found incompetent than defendants without such a diagnosis. It is important though, for evaluators to keep in mind that many defendants with such a diagnosis are considered to be competent. For example, Nicholson and Kugler (1991) reviewed 30 studies and concluded that defendants with psychotic disorders were more likely to be incompetent. They found 51% of defendants with a diagnosis of psychosis to be incompetent, compared to only 10% without this diagnosis. But note that an almost equal number of defendants with a diagnosis of psychosis are considered to be competent, making it clear that psychosis alone is not sufficient by itself to find a defendant incompetent. What is essential is to provide the link between the mental illness and the specific legal abilities required of a defendant in a particular case.

Cognitive deficits should also be a focus of an evaluation. Issues such as intellectual and developmental disabilities or cognitive deficits resulting from fetal alcohol spectrum disorder or other organic causes should be considered when appropriate in evaluations of competence (Cochrane, Grisso, & Frederick, 2001; Everington & Dunn, 1995; McLachlan, Roesch, Viljoen, & Douglas, 2014; Zapf, Roesch, & Pirelli, 2013).

Thus, once it is established that a person does have a mental disorder or cognitive deficits, the next step is to demonstrate how that mental disorder impairs a defendant’s legal abilities. Skeem and Golding (1998) suggest a three-step procedure for establishing a link between psychopathology and impairment of legal abilities: “one might (a) carefully consider the nature and content of the defendant’s primary symptoms, (b) consider how these symptoms might relate conceptually to the defendant’s specific psycholegal impairments, then (c) assess, as directly as possible, whether there actually is a relationship between the symptom and the CST impairment” (p. 364). Grisso emphasizes the contextual nature of a competency determination and the importance of understanding the demands of the defendant’s case, noting that “an interaction between individual ability and situational demand, not an absolute level of ability, is of special significance for competence decisions” (pp. 32–33).

Golding and Roesch (1988) defined the open-textured, context-dependent nature of the construct of competency to stand trial:

Mere presence of severe disturbance (a psychopathological criterion) is only a threshold issue—it must be further demonstrated that such severe disturbance in this defendant, facing these charges, in light of existing evidence, anticipating the substantial effort of a particular attorney with a relationship of known characteristics, results in the defendant being unable to rationally assist the attorney or to comprehend the nature of the proceedings and their likely outcome.

(p. 79)

The contextual nature of competence means that the necessary level of psycholegal abilities may vary depending on the nature of the legal proceedings expected of a defendant. For example, if a defendant is asked to testify, but is likely to withdraw into a catatonic state on the stand due to the stress of testimony, the defendant may be found incompetent, but this same defendant may be able to proceed if a plea bargain is the manner in which the case is resolved (Roesch, Zapf, Golding, & Skeem, 1999). As well, following the Edwards decision, a defendant could be found competent to stand trial but still denied the right to defend him or herself.

Evaluation of Competency

Evaluating competency is regarded as a less complex or difficult evaluation compared to an evaluation of criminal responsibility (i.e., an insanity defense). This is because a competency evaluation focuses on a defendant’s present mental state and its relationship to the ability to proceed with his or her case, whereas a criminal responsibility assessment requires a retrospective evaluation of past mental states. Occasionally, a court may request that both evaluations take place at the same time (Chauhan, Warren, Kois, & Wellbeloved-Stone, 2015).

Once a competency evaluation is ordered, the evaluation itself can take place in a range of settings, including jails, forensic facilities, or if a defendant is released on bail, in an outpatient setting. This represents a shift from the past in which nearly all evaluations were conducted in a central facility such as a forensic hospital. The shift to other settings has been driven in part by research showing that opinions about a defendant’s competence can be made after a relatively brief assessment (see Zapf & Roesch, 2009).

Research generally reports high agreement in studies of the reliability of CST evaluations, with agreement about the ultimate opinion regarding competency in the 90% range (Cox & Zapf, 2004; Poythress & Stock, 1980; Rosenfeld & Ritchie, 1998). However, most of the reliability studies examine agreement between two examiners using the same competency measure making dichotomous decisions about competence. Agreement about more specific psycholegal abilities is likely not as high. For example, Skeem, Golding, Cohn, and Berge (1998) found in a Utah study that 82% agreed about whether a defendant was competent or incompetent, but agreement dropped to about 25% on average for judgments about specific psycholegal abilities. Gowensmith et al. (2012) provide one of the few studies of evaluators in routine practice of conducting competency evaluations. Their “field reliability” study reviewed evaluators in over 200 cases, with each case requiring three independent evaluations by Hawaii law. Overall agreement (unanimous agreement among three evaluators) of initial evaluations of competency was lower than other studies (71%), which might be expected when more than two evaluators are studied. An interesting finding was that agreement dropped to 61% in reevaluations of defendants undergoing restoration after being found incompetent. Overall, these two studies suggest that while agreement between evaluators is generally high, there are a substantial number of cases in which evaluators disagree (18% in Utah and 29% in Hawaii). An interesting addition to the Gowensmith et al. study was their follow-up of the court decisions. Similar to other studies showing high concordance between evaluator recommendations and court decisions, judges agreed with the majority opinion in 92.5% of the initial evaluations, but this dropped to 77.4% in subsequent evaluations.

Murrie, Boccaccini, Zapf, Warren, and Henderson (2008) took a different approach to studying evaluator reliability by examining whether some evaluators find defendants incompetent more often than other evaluators. They drew on samples of 60 evaluators in Virginia and Alabama who had performed a minimum of 20 court-ordered evaluations, with a combined total of over 7,000 evaluations. There was considerable variation in opinions about incompetency, as the rates of incompetency determinations ranged from 0% to 62%. Some variability was due to clinician discipline (psychologists, psychiatrists, and social workers conducted the evaluations), which Murrie et al. speculated may have been due to differences in training and also how they viewed the relationship between psychosis and competence.

Validity of evaluators’ conclusions about competence is more difficult to assess, as there is no gold standard against which to compare evaluator opinions (Zapf & Roesch, 2009). Court outcome is an imperfect criterion as studies show that judges routinely accept the recommendations or opinions of evaluators, with agreement rates of over 90% (Cox & Zapf, 2004; Zapf, Hubbard, Cooper, Wheeles, & Ronan, 2004). In one attempt to identify a criterion, Golding, Roesch, and Schreiber (1984) used a panel of experts, referred to as a “blue ribbon panel,” to serve as an independent criterion. In their study, they asked two experts to make judgments about competency based on a review of records, reports from hospital evaluators, and evaluations using the Interdisciplinary Fitness Interview (IFI). They found that “for the 17 cases seen by the blue-ribbon panelists, they agreed with the IFI panelists 88% of the time, with the hospital staff 82% of the time, and with the courts 88% of the time,” and they concluded that “on the basis of these data it would be hard to argue for one criterion definition over another” (p. 331).

Competency Reports

There is no standard report format, but a number of sources provide guidelines that forensic evaluators can reference (Otto, DeMier, & Boccaccini, 2014; Zapf & Roesch, 2009). State laws typically do not specify what should be contained in a report, although the Utah statute is a clear exception. Utah courts can expect details about specific abilities, such as how to behave appropriately in court, testify relevantly if applicable, and whether medication is necessary and the impact it might have on the defendant’s demeanor, affect, and ability to participate in the proceedings (Utah Code Annotated, 2002). If incompetency is indicated, evaluators in Utah are also asked to specify treatment and whether the defendant can provide informed consent to treatment.

Research on report content suggests that many reports do not contain the details called for in Utah, as evaluators often fail to relate specific abilities and deficits to the particular case (Heilbrun & Collins, 1995). This appears to be true even in Utah despite specific legislation asking for such information. In their studies of reports of competency evaluators in Utah, Skeem et al. (1998) found that evaluators did review basic issues such as ability to assist counsel, but typically need not pay attention to decisional competence issues, as only 12% of the reports discussed whether the defendant understood what rights were given up when entering a guilty plea. They also noted that most defendants were on medication, but less than a fifth of the reports discussed the impact that might have on a defendant’s competency. Skeem, Golding, Cohn, and Berge (1998) called for more training and monitoring of evaluators. Similar findings were found in an Alabama study by Zapf, Hubbard, Cooper, Wheeles, and Ronan (2004), who examined reports in forensic facilities and found that while the majority of them covered factual understanding issues, over 90% offered no information about the “appreciation” or “reasoning” abilities of the defendants being evaluated for competency.

The decision about competency is ultimately one that rests in the hands of the presiding judge. An evaluator’s report to the court is presented as evidence that a judge may consider. A question has been raised about whether reports should offer an opinion about whether the defendant is competent or not (Slobogin, 1989). There is no explicit prohibition forbidding the offering of an ultimate opinion and, in many ways, a well-written report should make the evaluator’s opinion obvious even if it is not directly stated. Skeem and Golding (1998) argue that if the report educates the court about all relevant clinical factors, as well as how they are connected to the legal criteria, an opinion about the ultimate issue may simply be redundant. With respect to the preference of judges regarding report content, one study found that juvenile and criminal court judges from seven states stated they wanted ultimate opinions about competence and legal deficits more so than descriptions of causal explanations for psycholegal deficits (Viljoen, Wingrove, & Ryba, 2008).

Competency Measures

Evaluators may use psychological tests on occasion when it is thought to be helpful in identifying clinical constructs such as intelligence, psychopathology, or academic achievement. Evaluations conducted in the legal context should always consider the possibility of malingering since there may be motivation to feign or exaggerate symptoms with the intention of being found incompetent or for establishing an insanity defense later (Vitacco, Rogers, Gable, & Munizza, 2007). A number of instruments have been developed that may assist the examiner in evaluating the possibility of malingering (see Miller, 1995; Rogers, Bagby, & Dickens, 1992), including one designed specifically for feigning competence-related abilities (Guenther & Otto, 2010).

In addition to psychological tests, there are a number of forensic assessment instruments (FAIs) that may be helpful to evaluators, some of which also provide screens for assessing feigning of mental disorders (Rogers, Sewell, Grandjean, & Tillbrook, 2002). This section will provide a brief overview of possible FAIs that clinicians can use when evaluating competency. The choice of a specific FAI is of course a decision that must made by individual evaluators, as there is no standard that suggests that any single FAI must be used in all competency evaluations. Indeed, some evaluators may choose to use multiple FAIs for the same evaluation, as each type of FAI provides slightly different perspectives and information about a defendant’s competence.

The MacArthur Competence Assessment Tool-Criminal Adjudication (MacCAT-CA; Hoge, Bonnie, Poythress, & Monahan, 1999; Poythress et al., 1999) uses a hypothetical vignette to explore a defendant’s understanding, reasoning, and appreciation abilities. The vignette describes a bar fight between two men, Fred and Reggie, that results in an aggravated assault charge against Fred. The defendant is asked a series of questions about Fred’s situation and how Fred might deal with various aspects of his case. More details of the vignette are provided as the examiner moves through the first two sections of the MacCAT-CA. These sections assess a defendant’s ability to understand the legal issues and procedures, as well as their reasoning abilities. The items are scored on a 3-point scale with a score of 2 indicating full understanding of the item. For example, if the defendant adequately describes the role of a defense attorney, he or she would receive a score of 2. An interesting feature of the MacCAT-CA is that that an education component is built into the measure. If a defendant received a rating of less than a 2, the examiner provides the answer and then asks the defendant to repeat the provided answer in his or her own words. This provides an assessment of a defendant’s capacity to understand and acquire and process new information. A third section of the MacCAT-CA focuses on the defendants’ ability to appreciate his or her own legal circumstances and situation, and explores how they would make decisions in their actual case. These items are scored on the basis of the reasons that the defendant provides for his or her judgment and whether they are plausible or implausible (i.e., grounded in reality or based on delusional beliefs). The psychometric properties of the MacCAT-CA show that it is a reliable and valid instrument that is useful in assessing competency (Otto et al., 1998).

The Evaluation of Competency to Stand Trial-Revised (ECST-R; Rogers, Tillbrook, & Sewell, 2004) presents a clinical interview with both semi-structured and structured components. It provides an assessment of CST broadly, but also allows the clinician to address specific competencies that might arise in some cases, such as competency to plead and competency to proceed pro se. It assesses response style to provide an indication of malingering or feigning incompetency, as well as scale scores on four aspects of competency: factual understanding of the courtroom proceedings, rational understanding of the courtroom proceedings, consult with counsel, and overall rational ability. ECST-R items are rated by the clinician and provide a score on each of these scales. However, consistent with the functional approach to competency assessments, the scale scores are not summed to total one final score for the ECST-R, and no cut-offs are used to determine whether a defendant is competent or incompetent. The ECST-R demonstrates high internal consistency, with alpha coefficients for the competency scales ranging from .83–.89 and alpha coefficients for the feigning scales ranging from .63–.87. Inter-rater reliability for the ECST-R scales ranged from .91–1.00 (Rogers, Grandjean, Tillbrook, Vitacco, & Sewell, 2001; Rogers, Tillbrook, & Sewell, 2004).

The Fitness Interview Test-Revised (FIT-R; Roesch, Zapf, & Eaves, 2006) uses a semi-structured interview format to assess three main areas: (a) the ability to understand the nature or object of the proceedings, or factual knowledge of criminal procedure, (b) the ability to understand the possible consequences of the proceedings, or the appreciation of personal involvement in and importance of the proceedings, and (c) the ability to communicate with counsel, or to participate in the defense. Each of these three sections provides clinicians with specific questions that tap into different areas involved in competency. Each item is rated on a 3-point scale ranging from no impairment to definite or serious impairment. The FIT-R has been shown to have high inter-rater reliability and validity in studies comparing ratings by psychologists, psychiatrists, nurses, and psychology graduate students, and comparison of judgments based on the FIT-R with institutional-based evaluations of competency (Viljoen, Roesch, & Zapf, 2002a; Zapf, Roesch, & Viljoen, 2001), and high agreement with other competency measures such as the MacCAT-CA (Zapf & Roesch, 2001) and correlations with related constructs such as intelligence and psychosis (Viljoen, Roesch, & Zapf, 2002b; Viljoen, Zapf, & Roesch, 2003).

The Interdisciplinary Fitness Interview (IFI) was designed to assess both the legal and psychopathological aspects of competency (Golding et al., 1984), ideally involving interviews conducted by a psychologist and a lawyer team. The original IFI comprised three major sections assessing legal issues, psychopathological issues, and an overall evaluation of competency. The IFI was revised (Golding, 1993) and in its current form, the Interdisciplinary Fitness Interview-Revised taps 31 relatively specific psycholegal abilities organized into 11 global domains, addressing issues such as the iatrogenic effects of psychotropic medications (Riggins v. Nevada, 1992), a defendant’s decisional competency to engage in rational choice about trial strategies, decisions to represent oneself, and decisions about whether to plead or go to trial. The original IFI collected data from defendants interviewed by a two-person team, composed of a lawyer and either a psychologist or a social worker, and found high agreement about their final opinions of competency (Golding et al., 1984).

The Georgia Court Competency Test (GCCT) was developed by Wildman et al. (1978) as a screening device to screen out those defendants who were clearly competent. The original version included 17 items but a revised version, referred to as the GCCT-Mississippi State Hospital Revision (GCCT-MSH), has four additional items (Wildman, White, & Brandenburg, 1990). Some items require the defendant to visually identify the location of certain participants in the courtroom (i.e., defendants are shown a drawing of a courtroom and asked “where does the Judge sit?”), and then defendants are asked about the function of certain individuals in the courtroom, such as witnesses and lawyers. Each defendant is asked about the nature of the charges that he or she is facing, how the defendant would assist his or her lawyer, the nature of his or her relationship with the lawyer, and the consequences of a guilty verdict. Research on the GCCT-MSH indicates high levels of reliability and validity (Nicholson, Robertson, Johnson, & Jensen, 1988).

Competence Assessment for Standing Trial for defendants with Mental Retardation (CAST-MR) assesses the competence of defendants with intellectual deficits (Everington & Luckasson, 1992). The CAST-MR comprises 50 verbally administered questions that assess basic legal concepts, skills to assist defense, and understanding of case events. Items are scored based on the ability of the individual to relate information about his or her case in an accurate and understandable manner. There is limited research on the CAST-MR, but two studies indicated that the instrument has a level of reliability and validity comparable to other competency assessment instruments (Everington, 1990; Everington & Dunn, 1995).

The Competency Assessment Instrument (CAI; McGarry & Curran, 1973) was one of the early competency measures, used in the late 1960s. A semi-structured interview gathers information to score 13 items related to legal issues, such as “appraisal of available legal defenses,” “quality of relating to attorney,” “capacity to disclose pertinent facts,” and “capacity to testify relevantly.” Items are scored on a 5-point scale, ranging from “total incapacity” to “no incapacity.” The CAI manual contains clinical examples of levels of incapacity, as well as suggested interview questions. Limited research suggests that it can be a reliable and valid instrument used primarily as a guide for clinicians to focus on competence-related abilities (Nicholson & Kugler, 1991; Roesch & Golding, 1980).

The Competency Screening Test (CST) is a screening measure for identifying clearly competent defendants and thus avoiding inpatient evaluations (Lipsitt, Lelos, & McGarry, 1971). The CST has 22 item stems that ask defendants to complete sentences. Representative items are “Jack felt that the judge _____” or “If the jury finds me guilty _____.” Each item is given a score of 2 (competent), 1 (questionable), or 0 (incompetent), and scores below 20 would identify possible incompetent defendants, who would then be referred for further assessment, usually in an inpatient setting. Although the CST appears to be a reliable instrument (Nicholson et al., 1988; Randolph, Hicks, & Mason, 1981), concerns have been raised about its high false-positive rate because the majority of defendants screened as incompetent are later found to be competent in subsequent evaluations (Nicholson & Kugler, 1991).

Treatment of Incompetent Defendants

Prior to Jackson v. Indiana (1972), incompetent defendants would automatically be sent to a treatment facility for an indefinite period of time until competency was restored. For some, this resulted in confinement that lasted years and, for a few, a decade or more (Roesch & Golding, 1980), often spending more time in confinement than they would have been if convicted and sentenced on their original charges. This practice was challenged in Jackson. Theon Jackson, who was deaf and mute and could not read or write, was charged with two robberies and found incompetent due primarily to his inability to communicate and also his intellectual deficits. Treatment staff reported that his condition precluded his understanding the nature of charges against him and participating in his defense, and stated that there was no treatment that could help Jackson learn minimal communication skills. The U.S. Supreme Court held that defendants committed solely on the basis of incompetency “cannot be held more than the reasonable period of time necessary to determine whether there is a substantial probability that he will attain that capacity in the foreseeable future” (p. 738). Although the Court did not indicate how a reasonable period of time should be defined or progress toward regaining competency could be assessed, the decision made clear that if these two conditions were not met, the defendant would have to be released unless civil commitment was an appropriate alternative. The Jackson decision led to revisions in state statutes that provided alternatives to commitment and limited the length of commitment (Roesch & Golding, 1980). The duration of confinement varied from state to state, with some states providing maximum time limits (e.g., 18 months) while others tied treatment length to a proportion of the length of sentence that would have been given if the defendant had been convicted.

The Jackson decision raises the issue of whether it is possible to predict which incompetent defendants are unlikely to be restored. Mossman (2007) gives an example of a line of research that addresses this issue. He examined a sample of incompetent defendants in a restoration program and found that a number of factors were associated with a low probability of restoration, including a longstanding psychotic disorder, a diagnosis of mental retardation, and older age. However, the limited research has produced mixed results. Advokat, Guidry, Burnett, Manuno-Mire, and Thompson (2012) found that about 25% of their sample were considered not restorable, and noted few differences in terms of clinical diagnosis, substance abuse, intellectual capacity, or type of offense, but they also found that the group restored to competency performed better on the Georgia Court Competency Test and Global Assessment of Functioning scale at both initial and final assessments. This and other research (Hubbard & Zapf, 2003; Morris & Parker, 2008) suggests that it may be difficult to predict who will be restored, but this research is unlikely to affect court practice since most incompetent defendants are restored with treatment, so judges may decide to order treatment for a limited period even for those in a low success group.

Incompetent defendants are typically sent to residential forensic facilities, although outpatient treatment is an option (Miller, 2003). Treatment is usually relatively brief, as approximately 75% are restored to competency within six months and are returned at that point to court for the resumption of their criminal cases (Morris & Parker, 2008; Nicholson & McNulty, 1992). Warren, Chauhan, Kois, Dibble, and Knighton (2013) found a similar rate in a study of restoration of incompetent juveniles (see also McGaha, Otto, McClaren, & Petrila, 2001). Almost all incompetent defendants are returned to court within a year, with only a small percentage found to be unresponsive to treatment and thus not restorable. Because many defendants are found incompetent due to a psychosis, psychotropic medication is the most frequent type of treatment. The use of medication raises the question of whether an incompetent defendant can refuse to consent to being medicated. The issue reached the U.S. Supreme Court in the case of Sell v. United States (2003). Charles Sell was a dentist who was charged with fraud and attempted murder. He had a history of mental illness and although initially found competent, he later deteriorated and was found to be incompetent. He refused to consent to treatment, and the treatment facility attempted to force medication involuntarily. Sell appealed and the appellate court held that medication was necessary because he was dangerous to himself or others and medication was likely to restore competence. The Supreme Court held that medication could be forced but only in rare, limited circumstances in which it is found that “medication is substantially likely to render the defendant competent to stand trial and substantially unlikely to have side effects that will interfere significantly with the defendant’s ability to assist counsel in conducting a defense.” The Court also noted that it must be shown that less intrusive treatments are unlikely to restore competence.

The use of psychotropic medication has been shown to be effective in restoring competence, as evidenced by the high rate of restoration noted. An interesting question is whether involuntary medication would also prove effective in restoring competence. A recent study of defendants found incompetent in the federal court system (Cochrane, Herbel, Reardon, & Lloyd, 2013) found that 79% of 132 involuntarily medicated defendants were successfully restored to competence, with an average treatment period of less than five months.

One concern about restoring competence through medication is that defendants who are found competent and are proceeding with their criminal cases may discontinue taking medications. This was the case in Miles v. Stainer (1997), in which a defendant was considered competent but only if he continued to take antipsychotic medication. The Appeals Court held that the trial court erred because it was not aware that jail records indicated that the defendant had stopped taking his medication two weeks before entering a plea.

Less intrusive forms of treatment include legal rights education, deficit-focused remediation programs, and standard hospital treatment programs (Bertman et al., 2003). Unfortunately, there is little research on the effectiveness of various treatment approaches. One of the first to examine an education-focused approach, Siegel and Elwork (1990) found that incompetent defendants randomly assigned to an educational program that provided information on the legal process as well as problem-solving training showed significantly greater improvement on competency assessment instrument scores compared to a control group. Berman et al. also found improved scores on competency measures for incompetent defendants in legal rights education and deficit-focused remediation programs, but questioned whether the results were due to the greater individualized attention paid to the experimental group rather than the specific content of the programs. Incompetent defendants with intellectual deficits fare more poorly in restoration programs. Anderson and Hewitt (2002) reported only an 18% success rate, a finding supported by other studies (Pinals, 2005; Wall, Krupp, & Guilmette, 2003). Zapf and Roesch (2011), in their review of competency restoration programs, identified the pressing need for research “Focusing on specific cognitive deficits and symptoms of mental disorder and the interplay between these and various competency-related abilities and deficits” (p. 46).


Competency to participate fully in the defense of his or her criminal case is an essential right of a defendant to ensure a fair trial. The vast majority of defendants are competent to understand the charges against them, appreciate the legal consequences, make decisions about how to proceed with their cases, and able to communicate rationally with their attorneys. It is important, however, that mental health professionals are able to reliably and validly inform the court about the competency of defendants whose competence has been questioned by their lawyers, the prosecution, or the court. This article has provided an overview of forensic assessment instruments that have been developed to guide this process. For defendants found incompetent, treatment is usually successful in restoring competence and allowing them to return to court and proceed with the resolution of their cases.